Eugeniu Rosca <[email protected]> writes:
> The wl1837mod datasheet [1] says about the WL_IRQ pin:
>
> ---8<---
> SDIO available, interrupt out. Active high. [..]
> Set to rising edge (active high) on powerup.
> ---8<---
>
> That's the reason of seeing the interrupt configured as:
> - IRQ_TYPE_EDGE_RISING on HiKey 960/970
> - IRQ_TYPE_LEVEL_HIGH on a number of i.MX6 platforms
>
> We assert that all those platforms have the WL_IRQ pin connected
> to the SoC _directly_ (confirmed on HiKey 970 [2]).
>
> That's not the case for R-Car Kingfisher extension target, which carries
> a WL1837MODGIMOCT IC. There is an SN74LV1T04DBVR inverter present
> between the WLAN_IRQ pin of the WL18* chip and the SoC, effectively
> reversing the requirement quoted from [1]. IOW, in Kingfisher DTS
> configuration we would need to use IRQ_TYPE_EDGE_FALLING or
> IRQ_TYPE_LEVEL_LOW.
>
> Unfortunately, v4.2-rc1 commit bd763482c82ea2 ("wl18xx: wlan_irq:
> support platform dependent interrupt types") made a special case out
> of these interrupt types. After this commit, it is impossible to provide
> an IRQ configuration via DTS which would describe an inverter present
> between the WL18* chip and the SoC, generating the need for workarounds
> like [3].
>
> Create a boolean OF property, called "invert-irq" to specify that
> the WLAN_IRQ pin of WL18* is connected to the SoC via an inverter.
>
> This solution has been successfully tested on R-Car H3ULCB-KF-M06 using
> the DTS configuration [4] combined with the "invert-irq" property.
>
> [1] http://www.ti.com/lit/ds/symlink/wl1837mod.pdf
> [2] https://www.96boards.org/documentation/consumer/hikey/hikey970/hardware-docs/
> [3] https://github.com/CogentEmbedded/meta-rcar/blob/289fbd4f8354/meta-rcar-gen3-adas/recipes-kernel/linux/linux-renesas/0024-wl18xx-do-not-invert-IRQ-on-WLxxxx-side.patch
> [4] https://patchwork.kernel.org/patch/10895879/
> ("arm64: dts: ulcb-kf: Add support for TI WL1837")
>
> Signed-off-by: Eugeniu Rosca <[email protected]>
Tony&Eyal, do you agree with this?
--
Kalle Valo
Hi,
* Kalle Valo <[email protected]> [190610 07:01]:
> Eugeniu Rosca <[email protected]> writes:
>
> > The wl1837mod datasheet [1] says about the WL_IRQ pin:
> >
> > ---8<---
> > SDIO available, interrupt out. Active high. [..]
> > Set to rising edge (active high) on powerup.
> > ---8<---
> >
> > That's the reason of seeing the interrupt configured as:
> > - IRQ_TYPE_EDGE_RISING on HiKey 960/970
> > - IRQ_TYPE_LEVEL_HIGH on a number of i.MX6 platforms
> >
> > We assert that all those platforms have the WL_IRQ pin connected
> > to the SoC _directly_ (confirmed on HiKey 970 [2]).
> >
> > That's not the case for R-Car Kingfisher extension target, which carries
> > a WL1837MODGIMOCT IC. There is an SN74LV1T04DBVR inverter present
> > between the WLAN_IRQ pin of the WL18* chip and the SoC, effectively
> > reversing the requirement quoted from [1]. IOW, in Kingfisher DTS
> > configuration we would need to use IRQ_TYPE_EDGE_FALLING or
> > IRQ_TYPE_LEVEL_LOW.
> >
> > Unfortunately, v4.2-rc1 commit bd763482c82ea2 ("wl18xx: wlan_irq:
> > support platform dependent interrupt types") made a special case out
> > of these interrupt types. After this commit, it is impossible to provide
> > an IRQ configuration via DTS which would describe an inverter present
> > between the WL18* chip and the SoC, generating the need for workarounds
> > like [3].
> >
> > Create a boolean OF property, called "invert-irq" to specify that
> > the WLAN_IRQ pin of WL18* is connected to the SoC via an inverter.
> >
> > This solution has been successfully tested on R-Car H3ULCB-KF-M06 using
> > the DTS configuration [4] combined with the "invert-irq" property.
> >
> > [1] http://www.ti.com/lit/ds/symlink/wl1837mod.pdf
> > [2] https://www.96boards.org/documentation/consumer/hikey/hikey970/hardware-docs/
> > [3] https://github.com/CogentEmbedded/meta-rcar/blob/289fbd4f8354/meta-rcar-gen3-adas/recipes-kernel/linux/linux-renesas/0024-wl18xx-do-not-invert-IRQ-on-WLxxxx-side.patch
> > [4] https://patchwork.kernel.org/patch/10895879/
> > ("arm64: dts: ulcb-kf: Add support for TI WL1837")
> >
> > Signed-off-by: Eugeniu Rosca <[email protected]>
>
> Tony&Eyal, do you agree with this?
Yeah if there's some hardware between the WLAN device and the SoC
inverting the interrupt, I don't think we have clear a way to deal
with it short of setting up a separate irqchip that does the
translation.
But in some cases we also do not want to invert the interrupt, so
I think this property should take IRQ_TYPE_EDGE_RISING and
IRQ_TYPE_EDGE_RISING values to override the setting for
the WLAN end of the hardware?
Let's wait a bit longer for comments from Eyal too.
Regards,
Tony
CC irqchip
Original thread at
https://lore.kernel.org/lkml/[email protected]/
On Mon, Jun 10, 2019 at 10:30 AM Tony Lindgren <[email protected]> wrote:
> * Kalle Valo <[email protected]> [190610 07:01]:
> > Eugeniu Rosca <[email protected]> writes:
> >
> > > The wl1837mod datasheet [1] says about the WL_IRQ pin:
> > >
> > > ---8<---
> > > SDIO available, interrupt out. Active high. [..]
> > > Set to rising edge (active high) on powerup.
> > > ---8<---
> > >
> > > That's the reason of seeing the interrupt configured as:
> > > - IRQ_TYPE_EDGE_RISING on HiKey 960/970
> > > - IRQ_TYPE_LEVEL_HIGH on a number of i.MX6 platforms
> > >
> > > We assert that all those platforms have the WL_IRQ pin connected
> > > to the SoC _directly_ (confirmed on HiKey 970 [2]).
> > >
> > > That's not the case for R-Car Kingfisher extension target, which carries
> > > a WL1837MODGIMOCT IC. There is an SN74LV1T04DBVR inverter present
> > > between the WLAN_IRQ pin of the WL18* chip and the SoC, effectively
> > > reversing the requirement quoted from [1]. IOW, in Kingfisher DTS
> > > configuration we would need to use IRQ_TYPE_EDGE_FALLING or
> > > IRQ_TYPE_LEVEL_LOW.
> > >
> > > Unfortunately, v4.2-rc1 commit bd763482c82ea2 ("wl18xx: wlan_irq:
> > > support platform dependent interrupt types") made a special case out
> > > of these interrupt types. After this commit, it is impossible to provide
> > > an IRQ configuration via DTS which would describe an inverter present
> > > between the WL18* chip and the SoC, generating the need for workarounds
> > > like [3].
> > >
> > > Create a boolean OF property, called "invert-irq" to specify that
> > > the WLAN_IRQ pin of WL18* is connected to the SoC via an inverter.
> > >
> > > This solution has been successfully tested on R-Car H3ULCB-KF-M06 using
> > > the DTS configuration [4] combined with the "invert-irq" property.
> > >
> > > [1] http://www.ti.com/lit/ds/symlink/wl1837mod.pdf
> > > [2] https://www.96boards.org/documentation/consumer/hikey/hikey970/hardware-docs/
> > > [3] https://github.com/CogentEmbedded/meta-rcar/blob/289fbd4f8354/meta-rcar-gen3-adas/recipes-kernel/linux/linux-renesas/0024-wl18xx-do-not-invert-IRQ-on-WLxxxx-side.patch
> > > [4] https://patchwork.kernel.org/patch/10895879/
> > > ("arm64: dts: ulcb-kf: Add support for TI WL1837")
> > >
> > > Signed-off-by: Eugeniu Rosca <[email protected]>
> >
> > Tony&Eyal, do you agree with this?
>
> Yeah if there's some hardware between the WLAN device and the SoC
> inverting the interrupt, I don't think we have clear a way to deal
> with it short of setting up a separate irqchip that does the
> translation.
Yeah, inverting the interrupt type in DT works only for simple devices,
that don't need configuration.
A simple irqchip driver that just inverts the type sounds like a good
solution to me. Does something like that already exists?
> But in some cases we also do not want to invert the interrupt, so
> I think this property should take IRQ_TYPE_EDGE_RISING and
> IRQ_TYPE_EDGE_RISING values to override the setting for
> the WLAN end of the hardware?
>
> Let's wait a bit longer for comments from Eyal too.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
On 11/06/2019 09:45, Geert Uytterhoeven wrote:
> CC irqchip
>
> Original thread at
> https://lore.kernel.org/lkml/[email protected]/
>
> On Mon, Jun 10, 2019 at 10:30 AM Tony Lindgren <[email protected]> wrote:
>> * Kalle Valo <[email protected]> [190610 07:01]:
>>> Eugeniu Rosca <[email protected]> writes:
>>>
>>>> The wl1837mod datasheet [1] says about the WL_IRQ pin:
>>>>
>>>> ---8<---
>>>> SDIO available, interrupt out. Active high. [..]
>>>> Set to rising edge (active high) on powerup.
>>>> ---8<---
>>>>
>>>> That's the reason of seeing the interrupt configured as:
>>>> - IRQ_TYPE_EDGE_RISING on HiKey 960/970
>>>> - IRQ_TYPE_LEVEL_HIGH on a number of i.MX6 platforms
>>>>
>>>> We assert that all those platforms have the WL_IRQ pin connected
>>>> to the SoC _directly_ (confirmed on HiKey 970 [2]).
>>>>
>>>> That's not the case for R-Car Kingfisher extension target, which carries
>>>> a WL1837MODGIMOCT IC. There is an SN74LV1T04DBVR inverter present
>>>> between the WLAN_IRQ pin of the WL18* chip and the SoC, effectively
>>>> reversing the requirement quoted from [1]. IOW, in Kingfisher DTS
>>>> configuration we would need to use IRQ_TYPE_EDGE_FALLING or
>>>> IRQ_TYPE_LEVEL_LOW.
>>>>
>>>> Unfortunately, v4.2-rc1 commit bd763482c82ea2 ("wl18xx: wlan_irq:
>>>> support platform dependent interrupt types") made a special case out
>>>> of these interrupt types. After this commit, it is impossible to provide
>>>> an IRQ configuration via DTS which would describe an inverter present
>>>> between the WL18* chip and the SoC, generating the need for workarounds
>>>> like [3].
>>>>
>>>> Create a boolean OF property, called "invert-irq" to specify that
>>>> the WLAN_IRQ pin of WL18* is connected to the SoC via an inverter.
>>>>
>>>> This solution has been successfully tested on R-Car H3ULCB-KF-M06 using
>>>> the DTS configuration [4] combined with the "invert-irq" property.
>>>>
>>>> [1] http://www.ti.com/lit/ds/symlink/wl1837mod.pdf
>>>> [2] https://www.96boards.org/documentation/consumer/hikey/hikey970/hardware-docs/
>>>> [3] https://github.com/CogentEmbedded/meta-rcar/blob/289fbd4f8354/meta-rcar-gen3-adas/recipes-kernel/linux/linux-renesas/0024-wl18xx-do-not-invert-IRQ-on-WLxxxx-side.patch
>>>> [4] https://patchwork.kernel.org/patch/10895879/
>>>> ("arm64: dts: ulcb-kf: Add support for TI WL1837")
>>>>
>>>> Signed-off-by: Eugeniu Rosca <[email protected]>
>>>
>>> Tony&Eyal, do you agree with this?
>>
>> Yeah if there's some hardware between the WLAN device and the SoC
>> inverting the interrupt, I don't think we have clear a way to deal
>> with it short of setting up a separate irqchip that does the
>> translation.
>
> Yeah, inverting the interrupt type in DT works only for simple devices,
> that don't need configuration.
> A simple irqchip driver that just inverts the type sounds like a good
> solution to me. Does something like that already exists?
We already have plenty of that in the tree, the canonical example
probably being drivers/irqchip/irq-mtk-sysirq.c. It should be pretty
easy to turn this driver into something more generic.
Thanks,
M.
--
Jazz is not dead. It just smells funny...
Hi,
cc: Linus Walleij
On Tue, Jun 11, 2019 at 10:00:41AM +0100, Marc Zyngier wrote:
> On 11/06/2019 09:45, Geert Uytterhoeven wrote:
> > CC irqchip
> >
> > Original thread at
> > https://lore.kernel.org/lkml/[email protected]/
> >
> > On Mon, Jun 10, 2019 at 10:30 AM Tony Lindgren <[email protected]> wrote:
> >> * Kalle Valo <[email protected]> [190610 07:01]:
> >>> Eugeniu Rosca <[email protected]> writes:
> >>>
> >>>> The wl1837mod datasheet [1] says about the WL_IRQ pin:
> >>>>
> >>>> ---8<---
> >>>> SDIO available, interrupt out. Active high. [..]
> >>>> Set to rising edge (active high) on powerup.
> >>>> ---8<---
> >>>>
> >>>> That's the reason of seeing the interrupt configured as:
> >>>> - IRQ_TYPE_EDGE_RISING on HiKey 960/970
> >>>> - IRQ_TYPE_LEVEL_HIGH on a number of i.MX6 platforms
> >>>>
> >>>> We assert that all those platforms have the WL_IRQ pin connected
> >>>> to the SoC _directly_ (confirmed on HiKey 970 [2]).
> >>>>
> >>>> That's not the case for R-Car Kingfisher extension target, which carries
> >>>> a WL1837MODGIMOCT IC. There is an SN74LV1T04DBVR inverter present
> >>>> between the WLAN_IRQ pin of the WL18* chip and the SoC, effectively
> >>>> reversing the requirement quoted from [1]. IOW, in Kingfisher DTS
> >>>> configuration we would need to use IRQ_TYPE_EDGE_FALLING or
> >>>> IRQ_TYPE_LEVEL_LOW.
> >>>>
> >>>> Unfortunately, v4.2-rc1 commit bd763482c82ea2 ("wl18xx: wlan_irq:
> >>>> support platform dependent interrupt types") made a special case out
> >>>> of these interrupt types. After this commit, it is impossible to provide
> >>>> an IRQ configuration via DTS which would describe an inverter present
> >>>> between the WL18* chip and the SoC, generating the need for workarounds
> >>>> like [3].
> >>>>
> >>>> Create a boolean OF property, called "invert-irq" to specify that
> >>>> the WLAN_IRQ pin of WL18* is connected to the SoC via an inverter.
> >>>>
> >>>> This solution has been successfully tested on R-Car H3ULCB-KF-M06 using
> >>>> the DTS configuration [4] combined with the "invert-irq" property.
> >>>>
> >>>> [1] http://www.ti.com/lit/ds/symlink/wl1837mod.pdf
> >>>> [2] https://www.96boards.org/documentation/consumer/hikey/hikey970/hardware-docs/
> >>>> [3] https://github.com/CogentEmbedded/meta-rcar/blob/289fbd4f8354/meta-rcar-gen3-adas/recipes-kernel/linux/linux-renesas/0024-wl18xx-do-not-invert-IRQ-on-WLxxxx-side.patch
> >>>> [4] https://patchwork.kernel.org/patch/10895879/
> >>>> ("arm64: dts: ulcb-kf: Add support for TI WL1837")
> >>>>
> >>>> Signed-off-by: Eugeniu Rosca <[email protected]>
> >>>
> >>> Tony&Eyal, do you agree with this?
> >>
> >> Yeah if there's some hardware between the WLAN device and the SoC
> >> inverting the interrupt, I don't think we have clear a way to deal
> >> with it short of setting up a separate irqchip that does the
> >> translation.
> >
> > Yeah, inverting the interrupt type in DT works only for simple devices,
> > that don't need configuration.
> > A simple irqchip driver that just inverts the type sounds like a good
> > solution to me. Does something like that already exists?
>
> We already have plenty of that in the tree, the canonical example
> probably being drivers/irqchip/irq-mtk-sysirq.c. It should be pretty
> easy to turn this driver into something more generic.
I don't think drivers/irqchip/irq-mtk-sysirq.c can serve the
use-case/purpose of this patch. The MTK driver seems to be dealing with
the polarity inversion of on-SoC interrupts which are routed to GiC,
whereas in this patch we are talking about an off-chip interrupt
wired to R-Car GPIO controller.
It looks to me that the nice DTS sketch shared by Linus Walleij in [5]
might come closer to the concept proposed by Geert? FWIW, the
infrastructure/implementation to make this possible is still not ready.
One question to the wlcore/wl18xx maintainers: Why exactly do you give
freedom to users to set the interrupt as LEVEL_LOW/EDGE_FALLING [6]?
Apparently, this:
- complicates the wl18xx driver, thus increasing the chance for bugs
- is not supposed to reflect any HW differences between boards using
LEVEL_LOW/EDGE_FALLING and the boards using LEVEL_HIGH/EDGE_RISING
- doesn't bring any obvious advantage to the users, who are expected to
sense the same behavior regardless of the IRQ type set in DTS
- prevent the users to set IRQ type to LEVEL_LOW/EDGE_FALLING when
there is an inverter present between WL_IRQ and SoC
- seems to be not used almost at all, as 99% of mainline DTS set the
IRQ type to the canonical/NLCP LEVEL_HIGH/EDGE_RISING
[5] https://patchwork.ozlabs.org/patch/1095690/#2167076
("[V1,1/2] gpio: make it possible to set active-state on GPIO lines")
--------------------8<-------------------
gpio0: gpio {
compatible = "foo,chip";
gpio-controller;
(...)
};
inv0: inverter {
compatible = "inverter";
gpio-controller;
gpios = <&gpio0 0 GPIO_ACTIVE_HIGH>;
};
consumer {
compatible = "bar";
gpios = <&inv0 0 GPIO_ACTIVE_HIGH>;
};
--------------------8<-------------------
[6] bd763482c82ea2 ("wl18xx: wlan_irq: support platform dependent interrupt types")
--
Best Regards,
Eugeniu.